Text line diff

text-line-diff · version 1.0.0 · Text · free, no key needed

Diff two texts as line records, preserving each line terminator.

Use when you need to: text line diff · line record text diff · diff texts by lines.

Supported

• text line diff
• line record text diff
• diff texts by lines

Not supported

• fuzzy matching
• patience/histogram diff
• unicode normalization
• locale-aware line breaking
• binary patches
• git diff --git headers
• filesystem access

Behavior

• left and right are split with splitRecords: only CRLF, LF, and CR terminate lines.
• Record equality is text plus eol; the same characters with CRLF versus LF are different lines.
• Empty text yields no records; a missing final newline is stored as eol "".
• U+2028, U+2029, and U+FEFF stay inside line text and are not terminators.
• The Myers SES uses recordEqual; when D-paths tie, the library prefers delete from the left.
• Hunks come from hunksFromSes. context defaults to 3, may be 0, and is at most 16.
• Hunk op values are {text, eol} objects. identical is true iff there are no change ops.
• lines_left and lines_right are the record counts of left and right.
• Unknown input fields are rejected. Prototype-like line texts such as "__proto__" are ordinary strings.

Input

• left (string, required): max length 262144
• right (string, required): max length 262144
• context (integer, optional): min 0; max 16

Output

• hunks (array of object, required): max items 1024
• identical (boolean, required)
• lines_left (integer, required): min 0
• lines_right (integer, required): min 0

Limits

• max text bytes: 262144
• max line count: 4096
• max line bytes: 16384
• max context: 16
• max hunks: 1024
• max output bytes: 1048576

Example

Request input:

{
  "left": "a\nb\n",
  "right": "a\nc\n",
  "context": 0
}

Response:

{
  "result": {
    "hunks": [
      {
        "old_start": 1,
        "old_count": 1,
        "new_start": 1,
        "new_count": 1,
        "ops": [
          {
            "op": "delete",
            "value": {
              "text": "b",
              "eol": "\n"
            }
          },
          {
            "op": "insert",
            "value": {
              "text": "c",
              "eol": "\n"
            }
          }
        ]
      }
    ],
    "identical": false,
    "lines_left": 2,
    "lines_right": 2
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "text-line-diff",
  "version": "1.0.0",
  "input": {
    "left": "a\nb\n",
    "right": "a\nc\n",
    "context": 0
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/text-line-diff/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"left":"a\nb\n","right":"a\nc\n","context":0}'

The machine-readable contract is at /v1/tools/text-line-diff/versions/1.0.0.

CLI

node cli.mjs run text-line-diff 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Text word diff: Diff two texts as whitespace versus non-whitespace word tokens.
• Text diff stats: Summarize a line-record diff as keep, insert, delete, and hunk counts.
• Text lines chunk: Split parsed lines into consecutive chunks of size lines each.
• Text lines count: Count exact line multiplicities in first-seen order.
• Text lines difference: Set difference a minus b using exact line equality.
• Text lines multiset subtract: Multiset subtract b from a: remaining counts, first-seen order from a.